The present invention relates to an angiogenesis inhibitor containing as an active ingredient a protein-polysaccharide produced by extraction of mycelia or fruit bodies obtained from culture of a basidiomycete belonging to the genus Coriolus.
Blood vessels play very important roles in a biological field for living bodies, especially for animals having closed-cycle blood vessel system, for example, transporting nutrients to and taking away waste substances from tissues and/or organs in the bodies, which roles are indispensable to maintain the life of the bodies.
Accordingly, variety of researches relating to new formation of blood vessels, maintenance and improvement of their function etc. have been pursued so far subjecting the patients of suffering from high blood pressure, ischemic diseases, etc.
On the other hand, it has been gradually become clear that blood vessels playing such important roles which are essential to living bodies, sometimes extraordinarily proliferate and such proliferation induces several illness or makes some diseases worse. For example, recently it becomes known that certain percentage of patients of diabetes have unusual proliferation of capillary vessels in lens of eyeball and the patients occasionally become blind.
Further, when it comes to cancer diseases, which become top of the death causes in Japan, it is also known that capillary vessels of the host proliferate extraordinarily to the direction of cancer. [J. Folkman, page 85 to 97, SCIENTIFIC AMERICAN (Japanese Edition) Special Edition for Cancer, published by NIKKEI Science Co. on November 1981].
If there were no such unusual proliferation of blood vessels in a host, even if there existed a primary tumor, the tumor would not be able to grow to the size of more than several mm in its diameter and the host would not have any fatal symptom induced by such primary tumor. Accordingly, if one could inhibit or prevent such blood vessels proliferation, it becomes possible to prevent or cure several diseases induced by the proliferation.
So far, there have been known the substances having angiogenesis inhibiting activity such as anti-inflammatory medicines disclosed in Japanese Patent Application Laid-Open (KOKAI) 61-106,521 (1986) and Protamin disclosed in "Nature, vol. 297, pages 307 to 312 (1982)". However, both substances have some problems in view of their administration for a long period.
As a nature of this kind of medicines, it is necessary to administer for a long period, since the medicines become much less effective after capillary vessels have once reached to eye-lens or tumor and furthermore it is practically impossible to know in advance when the vessels start to proliferate. Therefore, to have safe medicines having substantially no side effect is extremely important.
The present inventors have extensively studied to find a substance which has angiogenesis inhibiting activity and which is extremely safe. As the result of their efforts, the present invention has been achieved.